A question about testing
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Our factory has recently been manufacturing three types of pressure vessels, among which grade III forgings are used quite frequently. In previous equipment manufacturing processes, it was found that many forgings had various issues regarding their material composition and physical-chemical properties; however, the samples provided by the manufacturers passed the re-inspection tests. I suspect that the manufacturer may not have taken samples from that batch of forgings; therefore, I plan to suggest that the forging manufacturer be present during sample collection. I wonder if there is any basis for such a request? Grade III forgings also require UT re-inspection, but it is difficult to conduct UT testing on the finished forgings once they arrive. I wonder how others solve this problem?
When placing the order, it’s sufficient to specify in the contract that supervision and inspection shall be carried out at the forging factory.
We have encountered this situation as well; as mentioned above, it’s sufficient to specify in the contract during ordering that supervision and inspection be carried out at the forging factory.
This is China’s national conditions! There are too many people who aren’t afraid of death! I think it’s possible to take samples on-site; no special basis is required – the user’s needs constitute that basis. Additionally, this can be considered as moving the inspection process forward, which makes sense. Some people say that carrying out supervision and inspection doesn’t seem very meaningful. I think there’s no need for me to explain that reason.
Is the UT inspection also carried out at the forging factory?
During UT testing, sometimes for structural reasons, it should be carried out after rough machining
This is specified and explained in the standards for forgings used in pressure vessels, along with ordering instructions and additional requirements in Appendix A (these requirements must be indicated at the time of contract signing). Regarding the ultrasonic testing of forgings, there are requirements regarding surface roughness; could it be that your company is having difficulties with the testing because the surface roughness does not meet the specified requirements? Personal opinion!
All the outsourced forgings produced by our company undergo UT inspection at the forging factory, and another UT inspection is carried out upon their return to our company, in order to prevent fraud by the manufacturers. It was done out of necessity.
If everything has to be sent to the forging factory for inspection, it will require a lot of manpower; it might even be necessary to have someone stationed there on a permanent basis, which is annoying
The small factories that produce forged parts are really dishonest these days. It is said that fake stainless steel can be used to replace 304 forged parts; I don’t know how they do that, but in any case the parts get corroded
This kind of situation happens far too often; there is a severe lack of self-discipline in the industry